Bow of Renewal

When you score a Critical Hit with this weapon you regain 1d4 + 1 Hit Points at the start of your turn for the next 1 minute. If you score a Critical Hit while under this effect, increase the Hit Points restored to 1d6 + 2, to a maximum of 1d8 + 3. Subsequent Critical Hits do not extend the duration of the effect. If you take Fire damage while under the effects of this property, the regeneration ends immediately.